Summary In daylight and clear weather with light winds, while proceeding toward Pier23, Hamilton Harbour, the deeply laden bulk cargo Utviken, with a pilot on board and with tug escort, struck the tanker HamiltonEnergy, and proceeded to strike and sink the tanker ProvmarTerminal. Substantial damage was sustained by both tankers, while the Utviken suffered damage in way of the bulbous bow, which caused flooding in the forepeak tank. There was minor pollution as a result of this occurrence. Ce rapport est galement disponible en franais. Other Factual Information Description of the Vessels The Utviken is a conventional bulk carrier, with bridge, accommodation and engine room located aft of the seven cargo holds. The vessel is fitted with a bulbous bow. On the fore and aft centre line, there are four cranes. The main engine, which requires air start from ahead to astern manoeuvres, drives a single-screw, right-handed propeller. The HamiltonEnergy is a small, single-hull tanker used for ship refuelling, primarily in Hamilton Harbour but also in western Lake Ontario. At the time of the occurrence, the vessel was tied up outboard of the ProvmarTerminal, starboard side to, on the north face of Pier24. The ProvmarTerminal is an oil storage vessel and maintains an engine room which contains boilers and generators. The vessel stores various grades of fuel and supplies the HamiltonEnergy with fuel cargo. Provmar FuelsInc. administrative offices are located in the aft accommodation area of the vessel. Located forward of the storage vessel and on the same pier, is the ProvmarTerminalII. This is an additional oil storage vessel, approximately the same size as the ProvmarTerminal. History of the Voyage The Utviken arrived at Hamilton Harbour anchorage at 1100 on 30March2001. At 1136 on 01April2001, a pilot boarded the Utviken in order to conduct the vessel to Pier23 in Hamilton Harbour. He was handed a pilot card and there was a brief exchange of information between the pilot and master concerning the vessel movement from the anchorage to Pier23. The pilot had conned this vessel to the same berth the previous year. At 1254, in clear weather and light winds, the Utviken departed the anchorage. On the bridge were the pilot, master, chief officer and helmsman. Two tugs, the PaulENo.1 (1200hp) and LacVancouver (700hp) had assisted in the departure of the vessel LakeSuperior from Pier23 and were now waiting near section 26 for the arrival of Utviken. Arrangements were made to pass the LakeSuperior, starboard to starboard, near section27. The manoeuvring room opposite the entrance to Pier23 was reduced by the presence of the bulk cargo Algocen berthed at section25. Having passed the LakeSuperior, and as the Utviken approached the tugs, one of the tugs' personnel observed that the vessel's speed was in excess of the typical speed for vessels attempting to berth at Pier23. At 1328, the tugs were following along on the port side not made fast, with PaulENo.1 forward adjacent to cargo hold No.1 and LacVancouver aft. Because of the northeasterly wind (astern), the Utviken had a tendency to turn to port while proceeding toward Pier23. Consequently, intermittent starboard wheel was used while coasting ahead. Additionally, the engine control setting was intermittently set at dead slow ahead, slow ahead and stop for the next nine minutes in order to maintain steerage way. There were four successful main engine air starts since the vessel departed the anchorage, two of which were between 1328 and 1337. In retrospect, the master thought the vessel's speed was faster than he was comfortable with under the circumstances, but he did not communicate his concerns to the pilot as he had confidence in the pilot's abilities. At 1337, the pilot ordered half-astern engine. The rpm indicator momentarily showed astern revolutions, but it quickly returned to the zero position. On his own initiative, the master ordered the starboard anchor to be let go in order to initiate a turning motion to starboard. In quick succession, the pilot then ordered both starboard and port anchors to be let go. Neither the master nor the pilot had specified a length of cable to be let out. The pilot then ordered the forward tug, PaulENo.1, to push with full power on the port side forward. The tug proceeded to push the Utviken at an angle of less than 90degrees to the hull due to the speed of advance. At 1338, the engine control was set to full astern. Again the rpm indicator momentarily showed astern revolutions but it quickly returned to zero. At 1339, the bridge control for the main engines was switched to engine room control and full-astern power developed some 15to 20seconds later. At about this time, a bridge team member observed that the global positioning system unit indicated a forward speed of 4knots. A crew member on the HamiltonEnergy, who had just come out on deck aft, could see a bow wave as the Utviken approached. Also at about this time, a person ashore, with considerable experience in securing vessels at Pier23, estimated the vessel's speed to be 5.5to 6knots. At 1340 to 1341, on a heading of approximately 170(T), the Utviken's bulbous bow struck the port quarter of the HamiltonEnergy, approximately 4m below the surface of the water in way of the skeg, propeller and rudder. The HamiltonEnergy was instantly heeled over to port (60to 70degrees), submerging the main deck port railing. The upper bow of the Utviken then collided with the aft superstructure of the HamiltonEnergy and slammed the vessel to starboard against the aft superstructure of the ProvmarTerminal. The HamiltonEnergy broke its moorings and drifted at speed, dead-ship, out into the harbour. While still moving forward and to starboard, the bulbous bow of the Utviken then penetrated the engine room spaces of the ProvmarTerminal, quickly sinking the stern of the vessel in a depth of approximately 10.5m. The chief engineer, who had been below in the engine room of the ProvmarTerminal, had just come on deck and was able to safely evacuate the vessel. Once the Utviken had lost all headway, the PaulENo.1 quickly proceeded to assist the HamiltonEnergy, which was drifting ahead in the middle of the southeast portion of the harbour. The Utviken was then backed away from the ProvmarTerminal and manoeuvred to her berth at Pier23, arriving at 1418. Some minor pollution around the stern of the ProvmarTerminal was quickly contained. Additional Information The vessel's navigation team tested the propulsion machinery and equipment prior to the anchor being weighed. The machinery was tested ahead and astern from both the wheelhouse and the engine room control. No further test was conducted subsequent to the pilot's boarding. The normal, bridge-controlled, starting sequence is automated and consists of two 18-rpm start attempts followed by one 35-rpm start attempt (at 30bar air pressure) before switching air tanks. Between 1337 and 1339, the bridge engine control failed to start the main engine at the half and full-astern settings, each with an attempted 18-rpm start. At 1339, the bridge control was switched to manual engine room control (which overrode the automated sequence), and the main engine was started. After the occurrence, the main engine pneumatic control system was inspected. Many pneumatic valves and Orings were overhauled or replaced within the system. It was discovered that the seal in a three-way starting air valve for the pneumatic main engine control system had deteriorated by some 50percent relative to original specifications. This valve is required for the opening of the starting air valve. This degradation of performance reduced the pressure of air delivered to start the engine. After the surveyed pneumatic control elements were either refurbished or replaced, between April01 and finishing April05, test starts were undertaken with a starting air pressure of 28.5bar. Sixteen bridge control starts were possible (randomly, ahead and astern) from this location before the low air pressure alarm sounded. Control was then passed to the engine room and a further 11starts were possible, with air pressure at 6bar for the final start. At the time of impact, there were three crew members aboard the HamiltonEnergy and one crew member aboard the ProvmarTerminal. No warning blast or general alarm was sounded by any of the vessels involved before or after the impact. Although a formal risk assessment of this area has not been undertaken by the Hamilton Harbour Commission (HHC),2 the HHC (HPA) recognizes that there are greater inherent risks associated with vessels proceeding to Pier23 than elsewhere in the harbour. Injuries to Persons The chief engineer of the HamiltonEnergy was thrown down a flight of steps at the point of impact. He suffered a sprained wrist and a cut on his hand. The other two crew members were violently tossed about at impact but suffered no personal injury. After the striking, many crew members on both tankers experienced symptoms similar to that of post-traumatic stress. Damage to the Vessels The HamiltonEnergy sustained heavy damage. The skeg was displaced approximately 1.5m and the propeller was damaged beyond further use. The rudder and pintle arrangement were significantly damaged and a thrust bearing became misaligned and distorted. The propeller shaft was driven inward, damaging the main engine block. The main engine installation was found to be a total loss. The steering gear flat and equipment sustained significant damage. The poop deck plating was deformed by 0.2to 0.4m in several locations. There was superstructure damage to the port and starboard side aft and the flag staff was bent over to at least 70degrees from the vertical. The ProvmarTerminal also suffered heavy damage. Penetration by the bulbous bow of Utviken created a 4.0m by 4.7m opening into the engine room spaces below the waterline. The subsequent flooding damaged boilers, generators and other electrical equipment. The Utviken suffered damage to the bulbous bow, which flooded the forepeak tank. Certification of the Vessels The Utviken was certified, equipped and crewed in accordance with existing regulations. The HamiltonEnergy and ProvmarTerminal had current inspection certificates issued by Transport Canada Marine Safety. Personnel Certification The pilot was appropriately licensed for the pilotage area of Lake Ontario and Kingston Harbour. The Utviken bridge and engine room personnel held qualifications appropriate for the class of vessel on which they were serving and for the voyage being undertaken. The tug masters were appropriately certificated. Personnel History The pilot had been with the Great Lakes Pilotage Authority since1993, working primarily on Lake Ontario and Kingston Harbour. He was familiar with Hamilton Harbour, having piloted vessels in and out of the harbour on many occasions. He piloted the Utviken to Pier23 the previous year (i.e.2000). The master had been in command of the Utviken for the last five years. He had made frequent trips to Hamilton and other Great Lake ports over the last nine years on this and other vessels. He had been master on the Utviken the previous year, when the same pilot conned the vessel to Pier23. Weather At 1300, Environment Canada recorded a wind speed and direction of 10knots at 70degrees for Hamilton Harbour. At 1400, it was 10knots at 50degrees. These readings were taken at the Burlington Bridge. Typically the wind speed at the bridge is slightly higher than at other areas within the Harbour. This would agree with the other observed speeds of 5to 8knots. Navigation Equipment There was a full range of navigation equipment on board, adequate for the safe operation of the vessel. No equipment malfunction was reported and the appropriate navigation chart was in use at the time of the occurrence. Main Engine Operation The vessel is fitted with pneumatic bridge controls for the operation of the main engine. The automated starting sequence consists of two 18-rpm start attempts before an attempt at a 35-rpm start. Reversing the engine requires that the main engine be stopped and reversed via air start control. At the push of a button on the bridge console, control reverts to the engine room. Starting attempts can also be made from the engine room control room position, either through the automated sequence or by manual means which overrides the 18-18-35rpm sequence. For engine room manual starting, the duration of the start attempt is then only limited by the amount of starting air available. On this ship, astern power is 75percent of ahead power. The engine response times are as follows: from stop to either ahead or astern propulsion, approximately 11-15seconds; and from stop, the propeller takes 15to 20seconds to reach the maximum of 100rpm. There were four successful main engine air starts since the vessel departed the anchorage, two of which were between 1328 and 1337. Vessel Manoeuvring Characteristics A dead slow ahead engine control setting gives the vessel a speed of 6.3knots. Information obtained from the manoeuvring diagram shows that the minimum speed for steerage way in the loaded condition is 4.1knots. Additionally, these diagrams show that in the loaded condition with the engine at slow ahead (8.2knots), a crash stop manoeuvre will produce an advance of 3cables and take 2.24minutes to come to a stop. At dead slow ahead, the distance and time required to execute a crash stop would be less. Depth of Water and Vessel Draught The height of water was 0.43m above the International Great Lakes Datum1955, and the depth of water as depicted on Canadian Hydrographic Service (CHS) chart No.2067 is 8.2m. The deepest reported draught of the Utviken was 7.92m. Vessel Speed and Squat As a vessel moves ahead in a shallow channel, the flow of water under the hull is accelerated and causes a reduction in pressure, such that the vessel settles deeper than her static mean draught. This phenomenon is known as squat and depends on the vessel's speed, the ratio of her static draught to the channel depth, and the relationship of the cross sectional areas of the hull and the channel. The amount of squat increases proportionally with the square of the vessel's speed, and loaded vessels with a limited underkeel clearance (UKC), when proceeding at too high a speed, may settle and make bottom contact. Observation and analysis of several hundred vessels operating at various speeds in relatively shallow water indicate that vessels similar to the Utviken with block coefficients of about0.8, tend to settle bodily and squat more by the bow. Stopping distances are typically indicated as derived during sea trials conducted in deep water. The Utviken was at maximum seaway draught when it was proceeding to Pier23 and, as such, had a static UKC of approximately 0.71m. When the main engine finally developed full-astern power, the propeller's bite of the water was reduced, in part due to the relatively low UKC, causing also a corresponding increase in the stopping distance and time. Visibility from the Bridge The disposition of the four cranes did not interfere with the navigational visibility from the bridge. Deployment of Tugs Two tugs were used to assist the vessel in manoeuvring/berthing: Neither tug was made fast to the Utviken because the pilot wanted the freedom to move the tugs along the length of the vessel as required and to avoid the tugs being caught between the Utviken and fixed structures in the area. Communication Between the Pilot and the Tugs The pilot communicated with the tugs by portable very high frequency (VHF) radiotelephone. There was no communication, however, between the time the tugs followed alongside until the last few minutes prior to the striking. Exchange of Information Between the Master and the Pilot The pilot was presented with the Pilot Card on boarding, and the exchange of information between the master and the pilot included the following main items: the ship was fitted with a fixed-pitch, right-handed propeller; astern propulsion would result in the bow going to starboard; astern propulsion was 75percent of ahead propulsion; and from ahead to astern or vice versa, the engine response time was 11-15seconds. The pilot/master exchange included the pilot's intended approach to Pier23. This was to be achieved by turning the vessel directly into the slip under her own power and without securing the tugs to the vessel; referred to as a running entry in this report. Previous Occurrence In a previous occurrence at the same location, HamiltonEnergy and ProvmarTerminal were struck by the bulk carrier Nirja as this vessel attempted a turn to starboard while berthing at Pier23, assisted by three tugs which were not made fast to the vessel.3